General toilet bowls installed in such as houses are too large in size for toddlers to use them. Therefore potty chairs have been used for the toddlers when they excrete. In addition, western style toilet bowls have been common these days. In order to allow the toddlers to utilize the western style toilet bowls, there have been used auxiliary toilet seats installed on a toilet seat of the western style toilet bowls. There are western style toilet bowls in various shapes and sizes. Therefore, the auxiliary toilet seats have adjustable fixing means so as to be fixed onto the toilet seat of the western style toilet bowls.
For example, publication of Japanese utility model registration number 3125037 discloses an auxiliary toilet seat for a toddler that includes first leg parts on a bottom surface thereof for abutting against a top surface of the toilet seat of the western style toilet bowl. Third leg parts are fixedly provided to a rear part of the bottom surface of the auxiliary toilet seat, which protrude downward so as to be abuttable against a bottom surface of the toilet seat of the western style toilet bowl. In addition, second leg parts are provided in a front part of the bottom surface of the auxiliary toilet seat as fixing means, which are formed adjustable so as to abut against an inner edge of the toilet seat of the western style toilet bowl to be fixed thereto. A handle is formed in a front part of the seating surface of the auxiliary toilet seat so as to be gripped by the toddler when being used.
When the toddler uses the auxiliary toilet seat disclosed in the publication of Japanese utility model registration number 3125037, the toddler sits astride the auxiliary toilet seat. At this time, the toddler also has to straddle the western style toilet bowl under the auxiliary toilet seat simultaneously, and this requires the toddler to open his/her legs widely when sitting on the auxiliary toilet seat. There are some toddlers who cannot excrete well or are unwilling to sit on the auxiliary toilet seat with their legs wide open. It is difficult to use the auxiliary toilet seat for such toddlers. In addition, when sitting astride the auxiliary toilet seat, the toddler has to take off his/her trousers and undergarment, which requires extra labor.